In a computer network, a communication flow may be defined by a plurality of messages (e.g., packets) between a source and a destination. Any time two devices interact over a packet network (e.g., the Internet), a communication flow can be defined by identifying all of the packets that are addressed from the first device to the second device. Since a communication flow may be bidirectional, the flow also includes all of the packets addressed from the second device to the first device.
NetFlow records allow data centers to monitor communication flows between virtual machines (VMs), as well as communication flows between VMs and outside services. This provides network visibility to network and data center administrators. Currently, Netflow records document the size of the communication flow (e.g., number of bytes, time duration), the source and destination addresses of the machines in the communication flow (e.g., Internet Protocol (IP) addresses and port numbers), as well as the application protocol of the communication flow (e.g., Hypertext Transfer Protocol (HTTP)).